RMR + EA + TEF + NEAT = TDEE
Remembering that this is likely to change each day depending on an unlimited number of variables. Trying to maintain, gain or lose weight by obsessing over mathematical formula is likely to leave you burnt out and disappointed.
Knowing a reasonable range of where your TDEE is however can allow you the knowledge to maintain, lose or gain weight depending on your goals. Likely the simplest way to look at your maintenance caloric requirements is to use an online calculator. This will provide you with an estimate based on your weight. Knowing then the rate of caloric expenditure from your exercise can be helpful as whether you want to gain or lose weight you should factor in this exercise.
Imagine a circuit style training consisting of resistance exercises and boxing for 45 minutes including your warm up and cool down. This is likely to burn approximately 260 calories for a 55kg person, 400 calories for an 85kg person and even more if you are heavier. These are simply guides as the level of intensity through to even the ambient temperature can affect these ranges. In fact, I read an interesting piece by Greg Nuckols where he sites this study and how 4 sets of 8 deadlifts at 175kg expends 100 calories. Now imagine if this formed just part of a gruelling 90 minute workout. immediately you can start to see how just lifting can really burn through the calories, not to mention adding in conditioning elements to the same workout. When you consider then that to gain weight you need a caloric surplus or to lose weight you need a caloric deficit you can start to consider how to achieve this.
Completing 3, 45 minute workouts like this per week for the 85kg person would mean an additional caloric expenditure of approximately 1200 calories per week. If that person’s goal was to lose weight this would be more than sufficient provided the calories ingested for that week did not exceed the TDEE. However don't forget the body compensates with homeostasis. It likes to stay where it is comfortable, meaning if you expend 1200 calories in a week the body will be sending out signals for extra calories to be consumed. This is why dieting is not easy, you have to fight against your bodies very nature. On the other hand, if the goal was to gain weight and the person was only receiving maintenance calories of their TDEE then additional meals would need to be added.
Ideally you can already see how the above formulas can become confusing. Therefore, below are some simple guidelines you can use:
* Weigh yourself only once a week.
* If your aim is to gain weight, seek no more than 500 grams (of weight gain) per week
* If your aim is to lose weight, you can look to achieve 1 kg (of weight lose) a week
* Whether you are seeking to gain or lose weight, prioritise protein at every meal
* For weight gainers add a cupped handful of carbohydrates (Pasta, rice etc) to 1 meal a day and monitor weight. If not gaining, add a second cupped handful to an additional meal per day.
* For people seeking to lose weight, reduce the equivalent of 1 cupped handful of carbohydrates from 1 meal a day then monitor. This might be as simple as removing the rice from your plate that you were having at lunch.
* High intensity exercise inclusive of resistance training is ideal to preserve and build muscle and lose unwanted fat. Hence the combined nature of resistance training and high intensity intervals is ideal for body composition purposes.
Keep things simple so you can monitor what you are doing and stay patient. Changing multiple things at once means it is difficult to ascertain what is working and what isn’t. Training hard, remaining consistent and methodical in your diet approach and keeping it simple will have you on track to achieve your personal goals.